Bladder With Improved Construction

ABSTRACT

The invention relates to a bladder and incorporation of a bladder in a shoe for cushioning a wearer&#39;s foot having an outsole, an upper, and a bladder adapted to receive the foot and being placed between the outsole and the upper. The bladder further has a first chamber and a second chamber, where the first chamber is in contact with the second chamber for providing continuous cushioning. The bladder is also removably placed between the upper and outsole. In other aspects of the invention, the bladder is integrally placed between the upper and outsole.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of co-pending U.S. patent application Ser. No. 11/220,086, which was filed on Sep. 6, 2005.

FIELD OF THE INVENTION

The invention relates to structures employed in shoes, protective equipment, and the like, for absorbing and dispersing energy.

BACKGROUND OF THE INVENTION

Structures for absorbing and dispersing mechanical energy are usually incorporated into shoes, sporting goods, clothing, protective equipment, vehicles, and the like to provide user comfort and safety. Such structures typically absorb and distribute kinetic energy to prevent damage or discomfort resulting from impacts. These structures may include football helmets, crash helmets, ballistic vests, and the like to minimize damage from energetic impacts.

Some energy absorbing and dispersing structures may be fabricated from polymeric foam materials of either the open or closed cell type. In other instances, such structures can be bodies of fibrous materials. Yet other instances may employ springs, pistons, and the like to be used as energy dispersing devices.

Shoes that typically employ a foam material often have a higher degree of resiliency. This can be accomplished by utilizing a relatively stiff open cell foam structure, or by going to a closed cell foam, or other such structure which possibly includes sealed air pockets. In either instance, the stiffer sole may provide adequate cushioning for high shock levels but is often rigid under low shock conditions, which could compromise comfort.

Some shoes known in the art may involve a variety of inflation devices disposed at different locations. For instance, previous shoe arrangements may have included soles that can be inflated at the arch to provide support. Other shoes typically have sealed inflated chambers disposed within the soles in order to increase vertical bounce. Such prior art shoes may not allow for selective adjustment of the pressure in the bladder chambers and may result in uneven air distribution in the sole of the shoe.

Moreover, if an impact force applied to such a structure exceeds its operational range, the structure may bottom out. In some instances, the structure will undergo irreversible break down. Bottoming out often occurs when a structure can absorb no more energy and ceases to provide any protection. For example, soles of shoes often include energy absorbing structures fabricated from open cell foam materials. However, when high levels of force are applied to these materials, as for example when the wearer jumps, runs, or stumbles, the cellular structure of the material typically flattens, and the innersole may bottom out allowing a jarring shock to be transmitted to a wearer's foot. Hence, the inflation device may be acceptable under low shock conditions but unacceptable, due to the bottoming out, under high shock conditions.

This bottoming out can be alleviated by providing a thicker body of foam material. However, such increases in thickness are generally unacceptable in footwear due to increase in bulk and instability. Furthermore, using a thicker body of foam in the sole of a shoe usually produces discomfort and fatigue.

Pumps in some prior art shoes have typically been either externally connectable to the shoe's air chambers or positioned in low stress areas on the upper portion of the shoe, such as in the tongue or on the back of the heel. For externally connectable pumps, the pump must be retrieved whenever inflation is desired. Pumps positioned on the upper portion possibly add bulk to the shoe and could limit agility. Such pumps also tend to inhibit aesthetic choices in shoe design.

U.S. Pat. No. 4,217,705 to Donzis appears to relate to an air filled chamber created by a top sheet and a bottom sheet sealed together around the entire periphery. The top and bottom sheets may be sealed together in select areas within the perimeter of the periphery to create a series of compartments that are in fluid connection with one another. Because the compartments may be in fluid communication with one another, a single type of fluid seems to be used to fill all compartments.

U.S. Pat. No. 4,446,634 to Johnson, U.S. Pat. No. 5,987,781 to Pavisi, U.S. Pat. No. 5,813,142 to Demon, U.S. Pat. No. 6,519,873 to Buttigieg, and U.S. Pat. No. 6,725,573 to Doyle appear to relate to a shoe with one or more chambers where all chambers have a single type of fluid contained within the chambers. In some of these references that have more than one chamber, the chambers seem to be spaced apart from one another.

What is desired, therefore, is a shoe with a cushioning device that has improved comfort and safety. Another desire is a shoe with a cushioning device that resists bottoming out. A further desire is a shoe with a cushioning device that permits adjustment to the cushioning device so that the shoe remains flexible during low shock conditions and is sufficiently rigid during high shock conditions.

SUMMARY OF THE INVENTION

It is, therefore, an object of the invention to provide a shoe that has an improved cushioning device.

Another object is a cushioning device that allows its physical properties to be varied in accordance with the intended use of the shoe.

A further object of the invention is to provide a cushioning device that includes separable internal chambers so that various fluids may be placed inside the chambers.

Yet another object is a cushioning device that provides continuous cushioning during transition from one chamber to a next chamber.

A still further object is a cushioning device that controls a fluid's movement during compression of the cushioning device so that the area of the cushioning device experiencing the compression resists complete decompression.

These and other objects are achieved by a shoe for cushioning a wearer's foot having an outsole, an upper, and a bladder adapted to receive the foot and being placed between the outsole and the upper. The bladder further has a first chamber and a second chamber, where the first chamber is in contact with the second chamber for providing continuous cushioning. The bladder is also removably placed between the upper and outsole. In other aspects of the invention, the bladder is integrally placed between the upper and outsole.

In some embodiments, the shoe has a first filler removably placed within the first chamber and the first filler includes a property selected from the group consisting of a user determined density, a user determined volume, a user determined weight, a user determined texture, a user determined consistency, and combinations thereof.

In other embodiments, the shoe has a baffle placed within the first chamber. In further embodiments, a socklining is placed on top of the bladder for receiving a wearer's foot.

In yet another embodiment, a distance between the first and second chambers is fixed. In some of these embodiments, the first chamber is adjacent to the second chamber.

In some other embodiments, a plurality of chambers and a plurality of fillers are provided, each filler corresponding to a chamber.

In another aspect of the invention, a shoe for cushioning a wearer's foot includes an outsole, an upper, and a bladder adapted to receive the foot and being placed between the outsole and the upper. The bladder also includes a first chamber and a second chamber, where the first chamber is adjacent to the second chamber for continuous cushioning and where the first chamber includes a first filler that is different than a second filler that is within the second chamber.

In some embodiments, a plurality of chambers and a plurality of fillers are provided, each filler corresponding to a chamber and where each filler is different from a next filler.

In other embodiments, the bladder includes a top sheet and a bottom sheet, where the top and bottom sheets are sealed together along a periphery of the top and bottom sheets. In some of these embodiments, the bladder includes a baffle for inhibiting movement of a first filler.

The baffle is a contact point between the top and bottom sheets within the periphery of the top and bottom sheets. In another embodiment, the baffle includes a wall with a top end connected to the top sheet and a bottom end connected to the bottom sheet. In addition to or instead of the above, the baffle is a permeable membrane.

In a more specific aspect of the invention, a bladder includes a top sheet having a periphery, a bottom sheet having a periphery, the top sheet being in contact with the bottom sheet along the peripheries of the top and bottom sheets, and where the top sheet is in contact with the bottom sheet in a localized area for defining a first chamber and a second chamber.

In some embodiments, the localized area extends across the top and bottom sheets from one side to an opposite side. Moreover, the first chamber includes an optional baffle for inhibiting movement of the first filler and/or the second filler. In some of these embodiments, the baffle is a contact point between the top and bottom sheets within the peripheries.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts the shoe in accordance with the invention.

FIG. 2 more particularly depicts the bladder shown in FIG. 1.

FIG. 3 depicts the bladder of FIG. 1 being compressed during usage.

FIGS. 4 a and 4 b shows the inside of the bladder shown in FIG. 1.

FIGS. 5 a-5 d show various applications of a baffle placed within the bladder of FIG. 1.

FIG. 6 a-6 c depicts another embodiment of the bladder shown in FIG. 1.

FIG. 7 depicts an application of the bladder shown in FIG. 1 in a shoe.

FIG. 8 depicts another application of the bladder shown in FIG. 1 in a shoe.

FIG. 9 depicts another application of the bladder shown in FIG. 1 in a shoe.

FIG. 10 depicts another application of the bladder shown in FIG. 1 in a shoe.

DETAILED DESCRIPTION

FIG. 1 depicts shoe 30 in accordance with the invention. Shoe 30 includes outsole 40, upper 50, and bladder 60 placed between outsole 40 and upper 60 for cushioning and/or supporting a user's foot. For enhanced comfort, socklining 41 is optionally placed on top of bladder 60 for receiving a user's foot. As more particularly depicted in FIG. 2, bladder 60 includes at least one chamber for containing a filler. As shown, bladder 60 includes first chamber 62, first filler 72, second chamber 64, second filler 74, third chamber 66, and third filler 76.

It is understood that although 3 chambers are shown, bladder 60 may include any number of chambers or a plurality of chambers, as well as a filler for each chamber including a plurality of fillers. The more chambers, the more bladder 60 may be filled with differing fillers of differing softness, density, or comfort in various areas of bladder 60. It is understood that the shape of a chamber is not germane to the invention.

In some embodiments, bladder 60 is removably placed between outsole 40 and upper 50 so that other bladders of varying characteristics may be utilized. This is advantageous when shoe 30 is used for different sports or in different environments and bladder 60 may be interchanged with another bladder rather than altering bladder 60. This reduces time especially if the process is to be repeated. In further embodiments, bladder 60 is integrally placed between outsole 40 and upper 50. This reduces the likelihood of bladder 60 from becoming accidentally dislodged.

For purposes of simplicity, first filler 72 will be described but it should be known that second filler 74, third filler 76, and a plurality of fillers all include the same limitations as first filler 72. Likewise, although first chamber 62 is described in detail below, it is understood that second chamber 74, third chamber 76, and a plurality of chambers all include the same limitations as first chamber 62. Moreover, although each filler is capable of being different than a next filler, it is not required. In some embodiments, two fillers are the same but a third filler is different. In other embodiments, all three fillers are different.

First filler 72 may be any solid, powder, liquid, or gas that may be placed within first chamber 62. The purpose of first filler 72 is to vary support, cushioning, and/or comfort to the wearer's foot depending upon the wearer's preferences. Hence, a density, volume, weight, texture, consistency, and any other property of the filler may be varied or user determined in any combination. For example, if a particular liquid does not provide adequate support, a different liquid may be utilized, where the second liquid may have a different density, buoyancy, texture, or weight. Therefore, when compressed by the foot, the wearer will experience the particular sensation, support, cushioning, or comfort unique to the particular filler. When a filler is defined to be different than a next filler, it means any of the properties or characteristics, or a combination for the properties or characteristics, listed herein is varied or changed.

In some instances where filler 72 is of a low viscosity, such as with some liquids, or where filler 72 is easily compressed, such as with some gases, first chamber 62 may be depressed to the point where there is no filler 72 in one part of first chamber 62, in which case little or no cushioning, support, or comfort may be derived from first filler 72. This may be due to compression of first chamber 62 from walking or running by a wearer.

During walking, the wearer typically strikes the heel first and then rolls to the middle of the foot and finally to the balls or toes of the foot. During this rolling, or gradual transition, from heel to toe, a chamber may be compressed on first part 44 and not second part 46, and vice versa (as shown in FIG. 3). This problem is exacerbated if first filler 72 is compressible or has a low viscosity.

As shown in FIG. 4 a, baffle 90 is any structure placed within any chamber for inhibiting movement of a filler. Baffle 90 is optional. In some embodiments, baffle 90 is placed in some chambers but not other chambers. For purposes of simplicity, baffle 90 will be described as shown within first chamber 62. However, any other chamber may also include baffle 90. In some embodiments, baffle 90 is a wall connected to roof 82 and floor 84 of first chamber 62. Baffle 90 may be angularly attached to roof 82 and floor 84 or attached to roof 82 and floor 84 at right angles, depending upon the resistance desired for inhibiting movement of the filler. In other embodiments, baffle 80 is attached to either roof 82 or floor 84 but not both. In simpler embodiments, baffler 80 is merely a contact point between roof 82 and floor 84 without any walls or structure to connect roof 82 with floor 84, which may be ineffective if the walls or structures become dislodged. In this fashion, melting or cementing roof 82 to floor 84 is less costly and easier to achieve the purpose of inhibiting movement of a filler than connecting a wall to roof 82 and floor 84. Moreover, melting or cementing roof 82 and floor 84 together to form baffle 90 can be done in the same operation as forming a chamber, which connects or seals a periphery of roof 82 and floor 84 together.

It is understood baffle 90 may extend partially or entirely across first chamber 62 from left side 86 to right side 88 or front side 87 to back side 89. Additionally, baffle 90 may be placed at an angle relative to the longitudinal axis of shoe 34, as shown more clearly in FIG. 4 b (a top view of chamber 62 and baffle 90). In order to vary the resistance to filler for inhibiting the movement of filler, the angle of baffle 90 relative to the longitudinal axis may be varied to inhibit more or less of the filler's movement. Moreover, baffle 90 may be placed at a different angle than a next baffle 91. Similarly, baffle 90 may be attached to top sheet 82 and bottom sheet 84 but baffle 91 may be attached only to bottom sheet 84. Also, the angle at which baffle is attached to roof 82 may vary from that of baffle 91. Still further, baffle 90 may extend at different lengths across chamber 62 than next baffle 91, whether it be from left side 86 to right side 88 and/or from front side 87 to back side 89.

In some embodiments of the invention, and in addition to or instead of the above description for baffle 90, baffle 90 includes permeable membrane 93. Membrane 93 is any thin, pliable sheet that acts like a filter that permits filler 72 to pass through but controls or slows the flow of filler 72, which results in a controlled or slowed depression, or compression, of bladder 60 when a user's foot presses down upon bladder 60. In some embodiments, permeable membrane 93 permits parts of filler 72, such as molecules containing Carbon, to pass through but may inhibit other parts of filler 72, such as molecules not containing Carbon, from passing through. This feature would act as, in addition to the presence of membrane 93 itself, another control to slow the flow of filler 72. FIGS. 5 a-5 d depict various applications of permeable membrane 93 in first chamber 62.

In this fashion, bladder 60 may be customized in a variety of different ways depending on what change or combination of changes are made to the properties of the filler. For example, besides changing the filler, a volume of a filler may be increased to enhance comfort or a filler may be a gel or solid to increase support or act as an orthodic. Moreover, the more chambers in bladder 60, the more adjustments may be made since each chamber may have a different filler with a different volume, density, or feel. Various types of materials for use as a filler include visco elastic or memory foam to mold to the shape of the user's foot, open and closed cell polyurethane foams, water, oil, helium, polyurethane gel, acrylic polymer gel, and the like. Additionally, baffle 90 further customizes bladder 60 by permitting flow control of filler 72, depending upon the orientation or material of baffle 90 and/or next baffle 91.

As shown, bladder 60 extends from toe area 36 to heel area 38 of shoe 30 and from left side 37 to right side 39 of shoe 30. Also as shown, membrane 93 extends from toe area 36 to heel area 38 and from left side 37 to right side 39. In some embodiments, bladder 60 extends partially across shoe 30. Also, as shown in FIGS. 5B-5D, membrane 93 extends partially across shoe 30 too.

It is understood that all chambers may be made of the same material and be the same size. In other embodiments, each chamber is of a different material than a next chamber. In further embodiments, each chamber is of a different size than a next chamber.

For example, first chamber 62 may be made of rubber while second chamber 64 may be made of a more resilient or elastic material. Different materials may be needed to accommodate different fillers. If first filler 72 is a liquid, first chamber 62 would be of a material strong enough to reduce rupture while also being leak resistant. Hence, rubber may be utilized. If second filler 74 is a gel, second chamber 62 may not necessitate a material that is particularly leak resistant if flexibility is more desired. Hence, a stretchable material such as cloth or spandex may be utilized to contain a gel. Perhaps a canvas type material is desired due to its strength rather that its leak resistance. Therefore, depending upon the type of filler and desired function of the chamber, the material for each chamber may vary or be the same as the next chamber.

The material of a chamber may also be selected depending upon any desired or undesired chemical reaction between the filler and the chamber. For example, if a filler contains hydrogen, the material selected for the chamber may be desired to be free from reaction with hydrogen. In other embodiments, the material may be desired to react with hydrogen so that, for example, water may be formed and act as a lubricant.

By having at least one chamber (first chamber 62, second chamber 64, and third chamber 66) in a side by side orientation as shown (see FIG. 2), bladder 60 improves comfort and provides continuous cushioning as bladder 60 transitions from chamber to chamber. This is because the chambers are in such close proximity to one another, and fixed in such positions since all chambers are fixedly attached together to form bladder 60, that the cushioning in bladder 60 feels continuous to a wearer.

Moreover, each chamber may be filled with a different filler than a next chamber so that areas of bladder 60 that are subjected to higher stress conditions, such as the heel, may be filled with a filler of higher resistance to compression and areas subjected to lower stress, such as the arch, may be filled with a filler of higher flexibility. By using different fillers in different chambers, bladder 60 provides flexibility in select areas and strength/stability in other areas.

Further, due to baffle 90, a chamber may be less likely to bottom out since the filler will be impeded from moving completely from one area of the chamber to another area of the chamber. In this fashion, baffle 90 helps prevent the chamber from bottoming out since there will be filler in all areas of the chamber, particularly in areas being subjected to stress.

The types of fillers that may be employed are all selected by a user, which may be the wearer or a manufacturer of bladder 60. The user selects a particular filler based on the filler's physical properties and the type of cushioning, strength, or rigidity desired as well as the projected environment in which shoe 30 is used.

As stated above, the filler is selected depending upon a variety of properties or characteristics of the filler. Below is table of the various properties of each filler. All properties are understood to be approximate.

POLY- URETHANE GEL FOAM WATER GEL OIL Density .35-.65 .20-.45 .96 .50-.75  .85-1.00 (g/cm³) Viscosity 600-800 n/a .89   800-1,200 400-600 (cps) Shore 00 40-50 30-40 n/a 50-70 n/a Durometer Weight of Use ≧200 ≧125 ≧100 ≧150 ≧135 (lbs)

FIGS. 6 a-6 c depict another embodiment of bladder 60 where wicking fabric 95 is secured to a top of surface of bladder 60. As shown, wicking fabric 95 is integrally attached to first chamber 62, second chamber 64, and third chamber 66 and where first chamber 62, second chamber 64, and third chamber 66 are separate from one another, although the spacing between the chambers resembles that of bladder 60 shown in FIG. 1. In the embodiment shown in FIGS. 6 a-6 c, wicking fabric 95 is adhered across the top of bladder 60 and effectively connects first chamber 62, second chamber 64, and third chamber 66 together. In this fashion, it would be redundant to further connect first chamber 62, second chamber 64, and third chamber 66 together as shown in FIG. 1 and then adhere wicking fabric 95 onto bladder 60. However, although first chamber 62, second chamber 64, and third chamber 66 shown in FIGS. 6 a-6 c are initially separate from one another, all three chambers achieve the same advantages of the embodiment shown in FIG. 1 when all are attached to wicking fabric 95. First chamber 62, second chamber 64, and third chamber 66 may each be independently attached to wicking fabric 95.

As shown, first chamber 62, second chamber 64, and third chamber 66 are all made of a solid gel or foam, such as a visco elastic memory foam, where the filler for each chamber and the chamber itself form a single unit. In other words, first chamber 62, second chamber 64, and third chamber 66 do not require a respective filler and, vice versa, the first, second, and third fillers do not require a respective chamber to contain each filler. This embodiment simplifies the invention by combining each filler together with each respective chamber.

Wicking fabric 95 is any material used to absorb moisture and/or odor away from the user's foot. Wicking fabric 95 may further include a bacteria reducing agent and/or fragrance emitting agent to reduce fungus and help the foot smell better.

In some embodiments, wicking fabric 95 is a two-layered composite having a cover layer and a foam layer that is hydrophilic with respect to the cover layer, which is operatively joined or connected or bonded or otherwise laminated in any suitable way to the cover layer as by needle punching, so that the composite material acts to draw or transfer moisture or bodily fluids from and through the cover layer into the foam layer which acts as a reservoir, to absorb, gel or store and dissipate such moisture or bodily fluid as by evaporation from or by washing of the composite material. After the moisture or bodily fluid is dissipated, from time to time, the composite material can be reused. However, those skilled in the art will recognize that the composite materials formed in accordance with the present invention can also be made of materials so that the composite material can also be disposable rather than reusable.

The foam layer may be first formed by polymerizing an aqueous mixture, having as its principal component one or more sorbents with or without various additives, with a predetermined quantity of a hydrophilic urethane prepolymer binder so that the polymerization of the polyurethane foam forms a matrix binder for the one or more sorbents. While the sorbents have been referred to as the principal component, it will be readily understood by those skilled in the art that the aqueous mixture may consist of various combinations of other components without departing from the scope of the present invention including absorptive fillers, fibrous materials, including non-woven fiber materials, surfactants, thermoformable acrylic latex emulsions, odor absorbents and bactericides. Further and additional components may include citric acid, rubber particles and thermal phase change particles depending on certain advantageous and desirable characteristics or functions to be achieved by the composite material.

The characteristics of the sorbent component may be selected so that the volume, rate of absorption and the retention or gelling of the moisture absorbed under varying ambient conditions of temperature and pressure may be optimized for a given composite material being formed. Preferred sorbents adapted for use in the aqueous mixture are primarily super absorbent polymers available in the commercial marketplace as SAB 800 from STOCKHAUSEN, Greensboro, N.C. 27406; as SANWET IM 1000 from Hoechst Celanese Corporation, Portsmouth Va. 23703; as ARIDAL 1460 from Chendal Corporation, Palatine, III. 60067; and as ARASORB 800F from Arakawa Chemical Industries, Limited, Osaka 541, Japan.

These sodium polyacrylate/polyalcohol polymer and co-polymer sorbents are manufactured and sold in free-flowing, discrete solid particles, in powder or granular form, and are characterized by the fact that they have a propensity for absorbing increasing quantities of aqueous fluid. This would normally lead to the complete solution of the polymers into the aqueous mixture. However, due to the chemical characteristics of the polymers and co-polymers, the formation of a gel takes place precluding the solution of the polymer or co-polymers. Other sorbents including polyethylene oxide, sodium carboxymethyl cellulose, and like polymers, desiccants such as silica gel, clays such as bentonite, and the like may be used as well.

Thus, when an aqueous mixture is metered and mixed with a hydrophilic urethane prepolymer, as more fully described below, the urethane prepolymer reacts with the water in the aqueous mixture to form a hydrophilic polyurethane foam, and at the same time when a sodium polyacrylate sorbent is present, the urethane prepolymer reacts with the sorbent to form a hydrophilic acrylic urethane interpolymer.

The combination of the sorbent with the hydrophilic foam thus formed acts in composite materials of either two larger or multiple layers to absorb, adsorb and gel the moisture drawn through the cover layer and to contain and store it so as not to rewet the cover top layer of the layered composite material. The sorbents thus add hydrophilicity to the foam layer of the composite materials.

The additives which may be combined in the aqueous mixture with the sorbents are also available in the commercial marketplace.

Thermoformable acrylic latex emulsions are available from Union Carbide Corporation of New York, N.Y., Rohm & Haas, B. F. Goodrich and others. One preferred form of acrylic emulsion is available from Union Carbide under the trademark “UCAR 154”. As is well known to those or ordinary skill in the art, latex emulsions are surfactant-stabilized polymer emulsions, and are commonly used as binders for non-woven materials. The thermoformable latexes form thermoplastic polymer films that are capable of being formed or molded when the film is heated above the glass transition temperature of the polymer.

Use of acrylic latex emulsions in the foam layer of the present invention thus serves as an alternative to the three-layer composite materials of the present invention wherein the third layer is a thermoformable non-woven material bonded to the side of the foam layer remote from the cover layer. The thermoformable acrylic latex emulsions are incorporated into the foam layer by including the emulsion as part of the aqueous mixture reacted with the hydrophilic urethane prepolymer. The water content of the emulsion reacts with the hydrophilic urethane prepolymer to form the polyurethane foam when the aqueous mixture and the urethane prepolymer are reacted together. Thus, the water content of the emulsion should be included as part of the water content of the aqueous mixture when calculating the ratio of the aqueous mixture to be reacted with the urethane prepolymer. Those of ordinary skill in the art will understand that the acrylate component contributed by the thermoformable acrylic latex emulsion is discrete and separate from the acrylate component contributed by the sodium polyacrylic sorbent, when present.

When the foam polymerization is complete, residual water is driven off by drying the foam at a temperature of about 200° F. After bonding of the foam layer to cover layer, the thermoformable acrylic latex, when present, permits the forming or molding of the composite by heating the composite in a mold or other form at a temperature above the glass transition temperature of the acrylic latex, typically a temperature of about 270° F., after which the composite is cooled and removed from the mold or form.

Surfactants useful in the combinations in accordance with the present invention are prepared from nonionic polyethylene and polypropylene oxides such as the BASF surfactant available under the trademark “PLURONIC”.

Odor absorption materials are also well known to those skilled in the art and include, activated carbon, green tea, “ABSENT” (UOP); zinc oxide and the like materials.

Bactericides are provided in the commercial marketplace by a myriad of suppliers for controlling bacterial and germ growth. One preferred material is supplied by Lauricidin Co. of Galena, III. 61036, under the trademark “LAURICIDIN”.

Phase change materials are capable of absorbing approximately 100 BTU/lb. These materials are described in U.S. Pat. Nos. 4,756,958 and 5,254,380.

Other components may be added to the aqueous mixtures, such as citric acid as a buffer for reducing the pH of the water component to increase loading of the sorbent and the fluid characteristic of the aqueous mixture to facilitate pumping of the aqueous mixture; and ground rubber particles from tires available from Composite Particles of Allentown, Pa. increase the resiliency and thermal protection of the composite material. These will be illustrated in the examples of the aqueous mixture more fully set forth below.

The hydrophilic urethane prepolymer component is also available in the commercial marketplace. Suitable prepolymers will be readily recognized by those of ordinary skill in the art and are described in U.S. Pat. Nos. 4,137,200; 4,209,605; 3,805,532; 2,993,013 and general procedures for the preparation and formation of such prepolymers can be found in Polyurethane's, Chemistry and Technology by J. H. Saunders and K. C. Frisch published by John Wiley & Sons, New York, N.Y., at Vol. XVI Part 2, High Polymer Series, “Foam Systems”, pages 7-26, and “Procedures for the Preparation of Polymers”, pages 26 et seq.

One preferred form of such prepolymer adapted for use in the present invention because of its strong hydrophilic characteristics and its reasonable price is marketed by Matrix R & D of Dover, N.H. as TDI/PEG Urethane Prepolymer under the trademark “BIPOL”. These products are polyether urethane polymers of toluene diisocyanate terminated polyethylene glycol with less than six percent (6%) available unreacted NCO groups and a component functionality of two (2) or less.

Another urethane prepolymer is available from W. R. Grace Company of New York, N.Y. sold under the trademark “HYPOL 3000”. This “HYPOL” urethane prepolymer is a polyisocyanate capped polyoxylene polyol prepolymer having a component functionality greater than two (2). However, this prepolymer is formulated with a triol which reduces its hydrophilic capability. Therefore, this “HYPOL” urethane prepolymer is less acceptable for the formation of the base layer of the composite material.

When the hydrophilic urethane prepolymer is added in precise amounts to the aqueous mixture, in addition to controlling the absorption characteristics of the final composite material, it has been found that it enhances the composite material so it can be sized and thermoformed into three-dimensional shapes such as the insole for shoes.

Thus, in the formation of the foam layer, a given aqueous mixture will be blended in ratios of 2 to 10 parts by weight of the aqueous mixture to 1 part by weight of the hydrophilic urethane prepolymer. Controlling in precise amounts the relative ratio of the aqueous mixture to the hydrophilic acrylic urethane prepolymer within these limits does not impair the capabilities of the super-absorbent polymer for absorbing and gelling moisture and body fluids with which the composite material comes into contact.

Another form of the composite material in accordance with the present invention in which the cover layer, foam layer hydrophilic with respect to the cover layer and a bottom or third layer is in the form of a non-woven fiber web or felted non-woven fiber web material. In this form of the composite material, the non-woven fibers selected are preferably those having stiffening or thermoforming capabilities.

Non-woven webs of fibrous materials for this purpose are available in the commercial marketplace as polyester non-woven fibers coated with acrylic resin from Union Wadding of Pawtucket, R.I.; Carr Lee of Rockleigh, N.J.; Stearns Kem Wove of Charlotte, N.C.; and Loren Products of Lawrence, Mass. Such polyester non-woven webs of fibrous material are used in the present invention because of their durability, adhesion to the components of the respective aqueous mixtures, because they act to reduce shrinkage during the secondary drying steps in the formation of the foam layer for the composite material being formed as is hereinafter described and because of the increase tensile strength they impart to thin films of the composite material, in accordance with the present invention, as those used in apparel and other products. Union Wadding supplies such preferred non-woven fibrous webs at 11/2 to 3 ounces per yard (¼″ to ½″ thickness). These are polyester 3 and 6 denier fiber acrylic spray bonded thermoformable materials. These products are formulated to enhance thermoformability of the multi-layered composite material.

Similarly felted non-woven webs of fibrous material are also available in the commercial marketplace from Non Wovens Inc. of North Chelmsford, Mass., who supply their products 8 oz. per square yard, 0.080 thickness, 65% low melt polyester and 35% high melt polyester. These felted non-woven webs of fiber material provide the same improved characteristics to the foam layer of the composite material in accordance with the present invention as has been above described.

It should be noted that non-woven materials may also be introduced as a component of the polyurethane foam layer, rather than being bonded to the foam layer as a discrete third layer. The addition of the non-woven material within the foam layer adds strength, minimizes shrinkage in drying and acts as a wick for moisture transpiration into the foam layer. Such foam layers are formed by depositing the polymerizing foam onto a non-woven fiber web and compressing the foam-coated web to 10% of its thickness, thus coating the fibers of the web with the polymerized foam containing interstitial voids.

In the embodiment of shoe 30 that employs wicking fabric 95, socklining 41 would be obviated as wicking fabric 95 would be in contact with the user's foot in order to wick moisture and/or odor away from the foot. In other embodiments, socklining 41 is placed beneath bladder 60 where bladder 60 is an insertable unit that may be interchanged with other bladders.

In an embodiment of an orthodic device, bladder 60 is used in accordance with certain guidelines, including Medicare requirements. These guidelines may change from year to year and bladder 60 and the shoe into which bladder 90 is inserted may change to conform to the guidelines. The following is an exemplary set of guidelines.

Therapeutic Shoes for Diabetics HCPCS Codes

A5500I—For diabetics only, fitting (including follow-up), custom preparation and supply of off-the-shelf depth-inlay shoe manufactured to accommodate multi-density insert(s), per shoe.

A550I—For diabetics only, fitting (including follow-up), custom preparation and supply of shoe molded from cast(s) of patient's foot (custom molded shoe), per shoe.

A5502—For diabetics only, multiple density insert(s), per shoe.

A5503—For diabetics only, modification (including fitting) of off-the-shelf depth-inlay shoe or custom-molded shoe with roller or rigid rocker bottom, per shoe.

A5504—For diabetics only, modification (including fitting) of off-the-shelf depth-inlay shoe or custom-molded shoe with wedge(s), per shoe.

A5505—For diabetics only, modification (including fitting) of off-the-shelf depth-inlay shoe or custom-molded shoe with metatarsal bar, per shoe.

A5506—For diabetics only, modification (including fitting) of off-the-shelf depth in-lay shoe or custom-molded shoe with off-set heel(s), per shoe.

A5507—For diabetics only, not otherwise specified modification (including fitting) of off-the-shelf depth-inlay or custom-molded shoe, per shoe.

L3649—Unlisted procedures for foot orthopedic shoes, shoe modification and transfers.

Benefit Category Therapeutic Shoes for Diabetics Definitions

A depth shoe (A5500) is one that 1) has a full-length heel-to-toe filler that when removed provides a minimum of 3/16″ of additional depth used to accommodate custom-molded or customized inserts, 2) is made from leather or other suitable material of equal quality, 3) has some form of shoe closure, and 4) is available in full and half sizes with a minimum of three widths so that the sole is graded to the size and width of the upper portions of the shoe according to the American standard last sizing schedule or its equivalent. (The American last sizing schedule is the numerical shoe sizing system used for shoes in the United States.) This includes a shoe with or without an internally seamless toe.

A custom-molded shoe (A5501) is one that 1) is constructed over a positive model of the patient's foot, 2) is made from leather or other suitable material of equal quality, 3) has removable inserts that can be altered or replaced as the patient's condition warrants, and 4) has some form of shoe closure. This includes a shoe with or without an internally seamless toe.

An insert (A5502) is a total contact, multiple density, removable inlay that is directly molded to the patient's foot or a model of the patient's foot and that is made of a suitable material with regard to the patient's condition.

Rigid rocker bottoms (A5503) are exterior elevations with apex position for 51 percent to 75 percent distance measured form the back end of the heel. The apex is a narrowed or pointed end of an anatomical structure. The apex must be positioned behind the metatarsal heads and tapering off sharply to the front tip of the sole. Apex height helps to eliminate pressure at the metatarsal heads.

Rigidity is ensured by the steel in the shoe. The heel of the shoe tapers off in the back in order to cause the heel to strike in the middle of the heel.

Roller bottoms (sole or bar) (A5503) are the same as rocker bottoms, but the heel is tapered from the apex to the front tip of the sole.

Wedges (posting) (A5504) are either of hind foot, fore foot, or both and may be in the middle or to the side. The function is to shift or transfer weight bearing upon standing or during ambulation to the opposite side for added support, stabilization, equalized weight distribution, or balance.

Metatarsal bars (A5505) are exterior bars which are placed behind the metatarsal heads in order to remove pressure from the metatarsal heads. The bars are of various shapes, heights, and construction depending on the exact purpose.

Offset heel (A5506) is a heel flanged at its base either in the middle, to the side, or a combination, that is then extended upward to the shoe in order to stabilize extreme positions of the hind foot.

Coverage and Payment Rules

Diabetic shoes, inserts, and/or modifications to the shoes are covered if the following criteria are met:

-   -   1) The patient has diabetes mellitus (ICD-9 diagnosis codes         250.00-250.91): and     -   2) The patient has one or more of the following conditions:         -   a) Previous amputation of the other foot, or part of either             foot, or         -   b) History of previous foot ulceration of either foot, or         -   c) History of pre-ulcerative calluses of either foot, or         -   d) Peripheral neuropathy with evidence of callus formation             of either foot, or         -   e) Foot deformity of either foot, or         -   f) Poor circulation in either foot; and     -   3) The physician who is managing the patient's systemic diabetes         condition has certified that indications 1 and 2 are met and         that he/she is treating the patient under a comprehensive plan         of care for his/her diabetes and that the patient needs diabetic         shoes.         -   For patients meeting these criteria, coverage is limited to             one of the following

within one calendar year:

-   -   -   -   1) One pair of custom molded shoes (A5501) (which                 includes inserts provided with these shoes) and 2                 additional pairs of inserts (A5502); or             -   2) One pair of depth shoes (A5500) and 3 pairs of                 inserts (A5502) (not including the non-customized                 removable inserts provided with such shoes).

Separate inserts may be covered and dispensed independently of diabetic shoes if the supplier of the shoes verifies in writing that the patient has appropriate footwear into which the insert can be placed. This footwear must meet the definitions found in this policy for depth shoes or custom-molded shoes. In addition, the inserts furnished must fully meet the definition of an insert set forth in this policy. Inserts, which will be used in noncovered shoes, are noncovered.

A custom molded shoe (A5501) is covered when the patient has a foot deformity, which cannot be accommodated by a depth shoe. The nature and severity of the deformity, which cannot be accommodated by a depth, shoe. The nature and severity of the deformity must be well documented in the supplier's records and may be requested by the DMERC. If there is insufficient justification for a custom molded show but the general coverage criteria are met, payment will be based on the allowance for the least costly medically appropriate alternative, A5500.

A modification of a custom molded or depth shoe will be covered as a substitute for an insert. Although not intended as a comprehensive list, the following are the most common shoe modifications: rigid rocker bottoms (A5503), roller bottoms (A5503), wedges (A5504), metatarsal bars (A5505), or offset heels (A5506). Other modifications to diabetic shoes (A5507) include, but are not limited to flared heels and inserts for missing toes.

Deluxe upgrades to diabetic shoes, including but not limited to style, color, or type of leather, will be denied as not medically necessary.

Shoes, inserts, and/or modifications that are provided to patients who do not meet the coverage criteria will be denied as noncovered. When codes are billed without a ZX modifier (see Documentation section), they will be denied as noncovered.

The particular type of footwear (shoes, inserts, modifications) which is necessary must be prescribed by a podiatrist or other qualified physician, knowledgeable in the fitting of diabetic shoes and inserts. The footwear must be fitted and furnished by a podiatrist or other qualified individual such as a pedorthist, orthotist or prosthetist. The certifying physician (i.e. the physician who manages the systemic diabetic condition) may not furnish the footwear unless he/she practices in a defined rural area or a defined health professional shortage area.

The prescribing physician (podiatrist or other qualified physician) can be the supplier (i.e. the one who furnishes the footwear).

There is no separate payment for the fitting of the shoes, inserts or modifications or for the certification of need or prescription of the footwear. Unrelated evaluation and management services by the physician are processed by the local carrier.

Coding Guidelines

Code A5507 is only to be used for not otherwise specified therapeutic modifications to the shoe. Code A5507 is not to be used for deluxe upgrades to diabetic shoes. At this time, deluxe features should be coded using code L3649.

A new HCPCS code will be established for deluxe features and will be published separately Therapeutic Shoes with its effective date.

A code for inserts or modifications (A5502-A5506, A5507) may only be used for items related to diabetic shoes (A5500, A5501). They should not be used for items related to footwear coded with codes L3215-L3253. Inserts and modifications used with L coded footwear should be coded using L codes (L3000-L3649).

When a single shoe, insert or modification is provided, the appropriate modifier, right (RT) or left (LT), should be used. If a pair is provided, report as two (2) units of service on the claim—the RT or LT modifiers should not be used.

Documentation

An order for the shoes, inserts or modifications which has been signed and dated by the prescribing physician must be kept on file by the supplier. If the prescribing physician is the supplier, a separate order is not required, but the item provided must be clearly noted in the patient's record. A new order is not required for the replacement of an insert or modification within one year of the order on file. However the supplier's records should document the reason for the replacement. A new order is required for the replacement of any shoe. A new order is also required for the replacement of an insert or modification more than one year from the most recent order on file.

The supplier should obtain a signed statement from the certifying physician specifying that the patient has diabetes mellitus, has one of conditions 2a-2f listed in the policy, is being treated under a comprehensive plan of care for his/her diabetes, and needs diabetic shoes. The Statement of Certifying Physician for Therapeutic Shoes developed by the DMERC is recommended. This statement may be completed by the prescribing physician or supplier but must be reviewed for accuracy of the information and signed by the certifying physician to indicate agreement. A new Certification Statement would be required for a shoe, insert or modification provided more than one-year form the most recent Certification Statement on file. If the supplier has a current signed statement on file that indicates that the coverage criteria described above has been met, then a ZX modifier should be added to the code. (ZX is a new modifier, which indicates “The specified coverage criteria in the medical policy have been met and documentation is available in the supplier's records”.) A diagnosis code for diabetes should be entered on the claim.

If code A5507 or L3649 is submitted, the claim must contain a narrative description of the modification or feature provided.

The prescribing physician's name and UPIN number should be listed in Blocks 17 and I7am of the HCFA 1500 form or the electronic equivalent.

Effective Date

Coverage and Payment Rules are effective for claims with dates of service on or after May 1, 1993 received by the DMERC. Use of the ZX modifier is required for claims received by the DMERC on or after Mar. 1, 1995.

Attention all Miscellaneous DMEPOS Suppliers:

Therapeutic Shoe Inserts—New Codes

Effective for dates of service on or after Apr. 1, 2004, the following new codes have been established for inserts for therapeutic shoes:

K0628 For diabetics only, multiple density insert, direct formed, molded to foot after external heat source of 230 degrees Fahrenheit or higher, total contact with patient's foot, including arch, base layer minimum of ‘4 inch material of shore a 35 durometer of 3116 inch material of Shore A 40 (or higher), prefabricated, each.

K0629 For diabetics only, multiple density insert, custom molded from model of patient's foot, total contact with patient's foot, including arch, base layer minimum of 3116 inch material of Shore a 35 durometer or higher, includes arch filer and other shaping material, custom fabricated, each

Codes A5509 and A5511 will be invalid for claim submission to the Durable Medical Equipment Regional Carrier (DMERC) for dates of service on or after Apr. 1, 2004. Under the standard grace period, these codes will continue to be accepted on claims with dates of service on or after Apr. 1, 2004 that are received by Jun. 30, 2004. Claims with these codes with dates of service on or after April 2004 that are received on or alter Jul. 1, 2004 will be rejected or denied as invalid coding. Codes A5509 and A5511 should continue to be used on claims with dates of service prior to Apr. 1, 2004 regardless of the date of claim submission.

Suppliers should contact the Statistical Analysis Durable Medical Equipment Regional Carrier (SADMERC) with any questions concerning the correct coding of specific items. Additional information concerning these codes can be found on the SADMERC Web site, www.palmettogba.com. Select Other Partners/SADMERC, then Coding Bulletins, then New Diabetic Shoe Insert Codes, A revision of the LMRP on Therapeutic Shoes for Diabetics incorporating these codes is included in the Match Region B DMERC Supplier Manual update.

This article is a result of CMS Publication 100-04, Change Request 3014, dated Jan. 2, 2004.

The following examples describe various applications of bladder 60 as used in other shoes.

Example 1 Drop-In Construction

As shown in FIG. 7, the drop-in construction shoe 102 includes footbed 106, outsole 108, spacer 110 placed on top of outsole 108 for providing structural integrity to shoe 102, and bladder 60 placed between footbed 106 and spacer 110. In another embodiment, bladder 60 is placed on top of footbed 106. Alternatively, footbed 106 may be eliminated since bladder 60 provides cushioning to the foot. Moreover, in addition to integrity, spacer 110 provides some cushioning to shoe 102.

Example 2 Stitch and Turn Construction

As shown in FIG. 8, the stitch and turn construction shoe 112 includes outsole 116, insole board 117 for providing integrity to shoe 112 and a level surface upon which the user's foot may rest, spacer 118 to raise the user's heel to a comfortable height, and footbed 120 to cushion the foot. Bladder 60 is thereafter placed between footbed 120 and spacer 118. In another embodiment, bladder 60 is placed on top of footbed 120. In the alternative, bladder 60 may replace footbed 120 or be placed between spacer 118 and insole board 117.

Example 3 Moccasin Construction

As shown in FIG. 9, the moccasin construction shoe 132 includes upper 134 that extends under and around the bottom of where a user's foot would be, this part of upper 134 being called vamp 138. Outsole 140 is then attached to a bottom of vamp 138. Optionally, cushion 142 is placed on a top of vamp 138. Socklining 139 would then be placed on top of cushion 142 to protect cushion 142 from wear and enhance comfort to the foot. In the event optional cushion 142 is utilized, bladder 60 is placed between cushion 142 and socklining 139. In another embodiment, bladder 60 is placed between cushion 142 and vamp 138. In a further embodiment, bladder 60 is used instead of cushion 142. In the event bladder 60 shown in FIG. 6 is employed, socklining 139 may be eliminated in the embodiments cushion 142 is eliminated.

Example 4 Opanka Construction

As shown in FIG. 10, the Opanka construction shoe 146 includes upper 148, bladder 60, and sole 150 all handsewn together in a single sewing operation. A socklining may also be used and sewn on top of bladder 60 in the same stitching operation. In the event the embodiment of bladder 60 shown in FIG. 6 is used, the socklining may be eliminated. As shown, the stitch is sewn around the entire perimeter of upper 148, bladder 60, sole 150, and the optional socklining (socklining not shown but the socklining has the same limitations as the above described socklinings). 

1. A shoe for cushioning a wearer's foot, comprising: an outsole; an upper; a bladder adapted to receive the foot and being placed between said outsole and said upper; said bladder includes a first chamber and a second chamber; said first chamber being adjacent to said second chamber for continuous cushioning; said first chamber includes a first filler; said second chamber includes a second filler; said first filler being different than said second filler; wherein said first chamber includes a baffle for inhibiting movement of said first filler; and wherein said baffle is a permeable membrane.
 2. The shoe according to claim 1, wherein said bladder includes a top sheet and a bottom sheet and said top and bottom sheets are sealed together along a periphery of said top and bottom sheets.
 3. The shoe according to claim 2, wherein said baffle contacts both of said top and bottom sheets within the periphery of said top and bottom sheets.
 4. The shoe according to claim 2, wherein said baffle comprises a wall with a top end connected to said top sheet and a bottom end connected to said bottom sheet.
 5. The shoe according to claim 1, wherein said first chamber is in contact with said second chamber.
 6. The shoe according to claim 1, further comprising a socklining placed on top of said bladder adapted to receive a wearer's foot, wherein the socklining is includes a wicking material.
 7. A shoe for cushioning a wearer's foot, comprising: an outsole; an upper; a bladder adapted to receive the foot and being placed between said outsole and said upper; said bladder includes a first chamber and a second chamber; said first chamber being adjacent to said second chamber for continuous cushioning; said first chamber includes a first filler; said second chamber includes a second filler; said first filler being different than said second filler; said first chamber including a first material to accommodate said first filler; and said second chamber including a second material to accommodate said second filler; wherein said first material is different from said second material.
 8. The shoe according to claim 7, wherein said bladder includes wicking material.
 9. The shoe according to claim 7, wherein said first filler is a liquid and said first chamber includes rubber.
 10. The shoe according to claim 7, wherein said second filler is a gel and said second chamber includes a cloth material. 